STAT3 and neoplasm: Together, these in vivo data confirm our in vitro data showing CCL2/CCR2/STAT3/EMT axis is an essential signalling pathway for AR silencing-mediated increased tumour metastasis, and provide new insights that combined targeting of both PCa AR and anti-CCL2/CCR2 axis may achieve the best therapeutic effects to suppress primary tumour PCa growth and metastasis.